Rigid hull inflatable boats are well known in prior art and have been used as transportation on the water whereby the inflatable members provide a buoyant force to keep the boat floating on water.
Chambered hull boats have been disclosed in the prior art and one such boat owned by Aluminum Chambered Boats, LLC of this application is U.S. Pat. No. 6,520,107 which disclose a multiple chambered boat where the chambers are positioned on the lateral end forward portions of the hull.
By way of background, stability tests are required for certain applications Coast Guard approval, and particularly for a commercial passenger service. Such stability tests position the maximum number of people the boat can hold is placed on one lateral side portion of the boat. With a normal type of boat, this will tip or seriously compromise the balance of the buyoancing forces adapted to handle the load.
It should be further noted that many military and law enforcement boats engage in a “fendering” operation with when these boats are approaching vessels at high speeds and do not allow for a great deal of time to de-accelerate the boat. The fendering maneuver is particularly useful in high-speed pursuit where the boat with the perimeter inflatable collar must engage a boat at sea, presumably under high speeds, de-accelerating such that the perimeter buoyant portion further allows for a certain amount of de-acceleration upon impact to prevent or mitigate damage to either vessel.
Many inflatable chambers as disclosed in the prior art comprise either rigid chambers or inflatable chambers in a mutually exclusive fashion. In such references such as U.S. Pat. No. 5,184,564, there is disclosed a perimeter buoyant member for a personal watercraft such as a jet ski. However, in a multi-passenger boat (where passengers can substantially reposition themselves about the craft), the center of gravity of the entire boat and load substantially shifts from the center longitudinal axis of the boat. This shifting of the center of gravity must be countered with a buoyant lifting force.
Further, in certain situations, it is very desirable to store the boat in a compact region such as in the central storage area of a C-130 aircraft. In such a situation, it is very desirable to store a deployable boat where the boat requires a minimum volume. However, in certain situations it is desirable to immediately deploy the boat without the need to invest time for preparing it in any manner. Therefore, providing a boat that has the buoyant properties with rigid buoyant chambers that independently provides a vertical floating buoyant force from the inflatable perimeter members provides a more robust safe design. By deflating the perimeter inflatable members, the net width and overall volume of the boat is reduced and yet by providing the redundant rigid sealed chambers, the boat is seaworthy in this state.